Phylogenetic tree morphological

Traditionally, phylogenetic trees were constructed relying on morphology and on the fossil records. Nowadays, however, they are constructed from comparisons of DNA or protein sequences in living organisms. Because of the antiquity of... 

Phylogenetic trees were generated by analyzing matrices of taxa (families of Haplosclerida) and characters (morphological, chemical) with the computer program PAUP 3.1.1 [87] in a Macintosh environment. Morphological characters are copied from De Weerdt [88], who is the only author who has formulated a detailed phylogeny of Haplosclerida families. Chemical characters are those discussed in the previous chapters, summarized in Table 4.1. 

FIGURE 4.1 Phylogenetic tree based on De Weerdt s [88] morphological character analysis. Black squares represent (syn)apomorphic characters of clades and terminal taxa. The tree is the result of a reanalysis of De Weerdt s data using PAUP 3.1.1 [87] (single most parsimonious tree). The taxon-character matrix is given in Table 4.2. 

Despite this, the advantages of investigating morphological characters with the help of molecular phylogenetic trees have become more evident during the past years. 

Figure 6.3 Larval morphology v ithin brachiopod subgroups, superimposed on a phylogenetic tree (the latter derived from various authors). If lecithotrophic brachiopod larvae are homo-logues, parsimony implies a lecithotrophic larva, equipped with larval setae, as the ancestral larval form (Larva of Neocrania anomala after Nielsen, 1991).

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